Why the drastic title, it's not that bad?
I really dont know what to tell you cos I have a 5yo cat that never poos in the tray, he never has and prob never will, just something I have to live with.
BTW, even when I had just the 2 cats he still never done in the tray so I dont know what his problem is?
Maybe your cat is anxious when your not there, maybe leaving a radio or tv on would help?